diff options
| -rw-r--r-- | synapse/storage/util/caches.py | 94 | ||||
| -rw-r--r-- | tests/util/test_dict_cache.py | 101 |
2 files changed, 195 insertions, 0 deletions
diff --git a/synapse/storage/util/caches.py b/synapse/storage/util/caches.py new file mode 100644 index 0000000000..0877cc79f6 --- /dev/null +++ b/synapse/storage/util/caches.py @@ -0,0 +1,94 @@ +# -*- coding: utf-8 -*- +# Copyright 2015 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from synapse.util.lrucache import LruCache +from collections import namedtuple +import threading + + +DictionaryEntry = namedtuple("DictionaryEntry", ("full", "value")) + + +class DictionaryCache(object): + + def __init__(self, name, max_entries=1000): + self.cache = LruCache(max_size=max_entries) + + self.name = name + self.sequence = 0 + self.thread = None + # caches_by_name[name] = self.cache + + class Sentinel(object): + __slots__ = [] + + self.sentinel = Sentinel() + + def check_thread(self): + expected_thread = self.thread + if expected_thread is None: + self.thread = threading.current_thread() + else: + if expected_thread is not threading.current_thread(): + raise ValueError( + "Cache objects can only be accessed from the main thread" + ) + + def get(self, key, dict_keys=None): + entry = self.cache.get(key, self.sentinel) + if entry is not self.sentinel: + # cache_counter.inc_hits(self.name) + + if dict_keys is None: + return DictionaryEntry(entry.full, dict(entry.value)) + else: + return DictionaryEntry(entry.full, { + k: entry.value[k] + for k in dict_keys + if k in entry.value + }) + + # cache_counter.inc_misses(self.name) + return DictionaryEntry(False, {}) + + def invalidate(self, key): + self.check_thread() + + # Increment the sequence number so that any SELECT statements that + # raced with the INSERT don't update the cache (SYN-369) + self.sequence += 1 + self.cache.pop(key, None) + + def invalidate_all(self): + self.check_thread() + self.sequence += 1 + self.cache.clear() + + def update(self, sequence, key, value, full=False): + self.check_thread() + if self.sequence == sequence: + # Only update the cache if the caches sequence number matches the + # number that the cache had before the SELECT was started (SYN-369) + if full: + self._insert(key, value) + else: + self._update_or_insert(key, value) + + def _update_or_insert(self, key, value): + entry = self.cache.setdefault(key, DictionaryEntry(False, {})) + entry.value.update(value) + + def _insert(self, key, value): + self.cache[key] = DictionaryEntry(True, value) diff --git a/tests/util/test_dict_cache.py b/tests/util/test_dict_cache.py new file mode 100644 index 0000000000..8cb9be6581 --- /dev/null +++ b/tests/util/test_dict_cache.py @@ -0,0 +1,101 @@ +# -*- coding: utf-8 -*- +# Copyright 2015 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + + +from twisted.internet import defer +from tests import unittest + +from synapse.storage.util.caches import DictionaryCache + + +class DictCacheTestCase(unittest.TestCase): + + def setUp(self): + self.cache = DictionaryCache("foobar") + + def test_simple_cache_hit_full(self): + key = "test_simple_cache_hit_full" + + v = self.cache.get(key) + self.assertEqual((False, {}), v) + + seq = self.cache.sequence + test_value = {"test": "test_simple_cache_hit_full"} + self.cache.update(seq, key, test_value, full=True) + + c = self.cache.get(key) + self.assertEqual(test_value, c.value) + + def test_simple_cache_hit_partial(self): + key = "test_simple_cache_hit_partial" + + seq = self.cache.sequence + test_value = { + "test": "test_simple_cache_hit_partial" + } + self.cache.update(seq, key, test_value, full=True) + + c = self.cache.get(key, ["test"]) + self.assertEqual(test_value, c.value) + + def test_simple_cache_miss_partial(self): + key = "test_simple_cache_miss_partial" + + seq = self.cache.sequence + test_value = { + "test": "test_simple_cache_miss_partial" + } + self.cache.update(seq, key, test_value, full=True) + + c = self.cache.get(key, ["test2"]) + self.assertEqual({}, c.value) + + def test_simple_cache_hit_miss_partial(self): + key = "test_simple_cache_hit_miss_partial" + + seq = self.cache.sequence + test_value = { + "test": "test_simple_cache_hit_miss_partial", + "test2": "test_simple_cache_hit_miss_partial2", + "test3": "test_simple_cache_hit_miss_partial3", + } + self.cache.update(seq, key, test_value, full=True) + + c = self.cache.get(key, ["test2"]) + self.assertEqual({"test2": "test_simple_cache_hit_miss_partial2"}, c.value) + + def test_multi_insert(self): + key = "test_simple_cache_hit_miss_partial" + + seq = self.cache.sequence + test_value_1 = { + "test": "test_simple_cache_hit_miss_partial", + } + self.cache.update(seq, key, test_value_1, full=False) + + seq = self.cache.sequence + test_value_2 = { + "test2": "test_simple_cache_hit_miss_partial2", + } + self.cache.update(seq, key, test_value_2, full=False) + + c = self.cache.get(key) + self.assertEqual( + { + "test": "test_simple_cache_hit_miss_partial", + "test2": "test_simple_cache_hit_miss_partial2", + }, + c.value + ) |